C#

泛型参数是不变的，c# 4.0为泛型类型引入了协方差和逆变性 可覆盖的类成员必须显式地标记为virtual

Java

缺少无符号数字数据类型 基本数据类型不是对象

VBA(因为你认为你的语言不好)

Whitespace inside a line is rigidly enforced. Statements just end, and require a " _" to break to the next line, but not every line can be broken. No ++,--,+=,-= statements. Seriously? Arrays can begin at any index, not just 0. Some types (i.e.: fixed-point "Decimal" value) must be subtypes of Variant, and aren't available as their own type. != and <>. "=" is used as both comparator and assigning, instead of splitting into "=" and "==". "Option Explicit". UI hasn't been updated since 2000. Office2k7 didn't upgrade to VB.NET Most object models are non-sensical and overly verbose.

Java

已检查的异常 类型擦除 缺少操作符重载(例如BigInteger/BigDecimal) 缺少regexp/date/duration /复杂文字 对不可变性的支持很差

Haskell

Sometimes the type system feels backwards. What if I don't want the compiler to infer types for my variables? What if I want the opposite, where it does constraint checking on said variables? For example, instead of inferring the type of the elements of a list, it instead makes sure that they all belong to a particular typeclass. This is a subtle but huge difference that makes it difficult for me to program UIs. It can be done, but it takes more effort than it does in some other languages. Haskell rocks for the non-UI parts, but the UI I leave to an untyped language. Allowing the construction of infinite values leads to some really frustrating errors sometimes. NoMonomorphismRestriction. Bytestring handling bites me in the ass sometimes and you don't know it until your program crashes because you mixed them up improperly. Something is wrong here, when we are losing type information that should have prevented this. Typeclasses should be automatically derived for trivial cases, like witness types, but there's a strong potential for abuse there.

Python,:

No switch keyword. And NO, dictionary is not a replacement for it. Not even a bunch of elif statements. Inconsistent line break handling. Why can I do: test = (1, 2, 3) And not: from itertools import cycle, islice, izip Why can't I do: if stuff \ and foo \ or bar: return "Formated string with %(arg)s" % \ {'arg': "bloody slash"} without using slashes? There is not one obvious and only one way to do it. Python fails on its motto just like Java failed on "Write once run anywhere". # what somebody from an another language would do if not test.has_key('foo'): test['foo'] = 0 n = test['foo'] = test['foo'] + 1 vs # what an agnostic beginer would do try: test['foo'] += 1 except KeyError: test['foo'] = 1 n = test['foo'] vs # what you end up after looking for dictionary default value in the python doc test.setdefault('foo', 0) n = test['foo'] = test['foo'] + 1 vs # what I would do n = test['foo'] = test.get('foo', 0) + 1 And the worst is that they don't do exactly the same thing. There are subtle differences. Choice between spaces and tabs. There should be no choice. Pick on, set it in stone and stop fighting. Why can you do that: test = {} test['foo'] = 0 but not: test = [] test[] = 0

附注:" ".join(l)是优秀的人。不要抱怨它，这并不明显，但考虑到迭代器模式，这是正确的方法。

length属性很容易与length()函数混淆;请改用size() 在选择器字符串中插入变量的语法('" +$。Month + "')臭死了 $(event.currentTarget)并不总是适用于冒泡和捕获 属性语法("[class='foot']")在选择器语法(".foot")不返回任何结果的地方起作用 包含选择器([class~=done])有时会在JavaScript (this.className.search("done") > 0)工作时失败